Motor Drive Circuit and Illumination Apparatus
First Claim
1. A motor drive circuit comprising:
- an output transistor configured to supply a drive current to a drive coil of a motor configured to cause a fan to rotate so as to blow air to cool an object to be cooled;
a switching control circuit configured to control switching of the output transistor so that the motor rotates in a first direction to cool the object to be cooled, or rotates in a second direction opposite to the first direction; and
a switching circuitconfigured to, when a first time has elapsed since start of rotation of the motor in the first direction, cause the switching control circuit to start switching control so that the motor stops rotating in the first direction and thereafter rotates in the second direction, andconfigured to, when a second time has elapsed since start of rotation of the motor in the second direction, cause the switching control circuit to start switching control so that the motor stops rotating in the second direction and thereafter rotates in the first direction.
5 Assignments
0 Petitions
Accused Products
Abstract
A motor-drive circuit includes: an output transistor configured to supply a drive current to a motor for a cooling fan; a switching-control circuit configured to control switching of the output transistor so that the motor rotates in a first direction, or rotates in a second direction opposite to the first direction; and a switching circuit configured to, when a first time has elapsed since start of rotation of the motor in the first direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the first direction and thereafter rotates in the second direction, and configured to, when a second time has elapsed since start of rotation of the motor in the second direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the second direction and thereafter rotates in the first direction.
16 Citations
11 Claims
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1. A motor drive circuit comprising:
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an output transistor configured to supply a drive current to a drive coil of a motor configured to cause a fan to rotate so as to blow air to cool an object to be cooled; a switching control circuit configured to control switching of the output transistor so that the motor rotates in a first direction to cool the object to be cooled, or rotates in a second direction opposite to the first direction; and a switching circuit configured to, when a first time has elapsed since start of rotation of the motor in the first direction, cause the switching control circuit to start switching control so that the motor stops rotating in the first direction and thereafter rotates in the second direction, and configured to, when a second time has elapsed since start of rotation of the motor in the second direction, cause the switching control circuit to start switching control so that the motor stops rotating in the second direction and thereafter rotates in the first direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification